01-02-2008, 10:46 AM
i think i'm getting a better idea of why the RS pings so badly on anything less than 93:
![[Image: afr_load_vs_rpm.jpg]](http://www.siriusphoto.com/forum_posts/afr_load_vs_rpm.jpg)
^^ graph taken from a car being logged from 2k rpm to redline. this is the factory tune. basically the car is trying to stay stoich until going pig rich like someone hit an on/off switch -- dyno tunes confirm that power plummets at high rpms for this reason. odds are subaru has it tuned this way to keep fuel milage high in the typical "highway" rpms. i've heard of WRX's in later years being tuned like this from the factory as well.
i've never expereinced pinging above 5k rpm either, which now makes sense. looks like i may consider getting the car tuned so i can run 87 but keep the same horsepower....maybe actually gain some (remember, i bought the car to be a cheapskate but still have fun, so i want to run piss-gas).
^^ graph taken from a car being logged from 2k rpm to redline. this is the factory tune. basically the car is trying to stay stoich until going pig rich like someone hit an on/off switch -- dyno tunes confirm that power plummets at high rpms for this reason. odds are subaru has it tuned this way to keep fuel milage high in the typical "highway" rpms. i've heard of WRX's in later years being tuned like this from the factory as well.
i've never expereinced pinging above 5k rpm either, which now makes sense. looks like i may consider getting the car tuned so i can run 87 but keep the same horsepower....maybe actually gain some (remember, i bought the car to be a cheapskate but still have fun, so i want to run piss-gas).
2010 Civic Si
2019 4Runner TRD Off-Road
--------------------------
Past: 03 Xterra SE 4x4 | 05 Impreza 2.5RS | 99.5 A4 Quattro 1.8T | 01 Accord EX | 90 Maxima GXE | 96 Explorer XLT
2019 4Runner TRD Off-Road
--------------------------
Past: 03 Xterra SE 4x4 | 05 Impreza 2.5RS | 99.5 A4 Quattro 1.8T | 01 Accord EX | 90 Maxima GXE | 96 Explorer XLT